Two views of why Tyre and Sidon would more likely repent than Chorazin and Bethsaida:
The pagan Tyre and Sidon were judged in the Old Testament for their wickedness, especially Tyre (Amos 1:9–10;Isaiah 23:1–18; Jeremiah 25:22, Jeremiah 47:4; Ezekiel 26:1–28:26). Chorazin and Bethsaida will be judged more harshly than Tyre and Sidon, due to their greater opportunities to hear and see the gospel (Matthew 20:23–24,Jeremiah 10:15, John 15:24).
The unbelief of these cities shows their foolishness (Matthew 11:21). Any Gentile city would have responded differently. While Tyre and Sidon did not repent when Isaiah (see Isaiah 23:1–18) or Ezekiel (see Ezekiel 26:1–28:26) prophesied against them, they would certainly have repented and turned to the Lord if Jesus had performed his mighty works in their streets. They would have sat in sackcloth and ashes. This shows how Chorazin and Bethsaida were even more foolish than the blind Gentiles of the two pagan cities.
Interpretation 1:
Tyre and Sidon were pagan cities located in Syro-Phoenicia situated on the coast of the Mediterranean Sea. In the Old Testament they were, because of their wickedness—especially Tyre—the object of divine wrath: see Amos 1:9–10; Isaiah 23:1–18; Jeremiah 25:22, Jeremiah 47:4; Ezekiel 26:1–28:26. Chorazin and Bethsaida, however, will be judged more severely than Tyre and Sidon, for judgment stands in direct proportion to the opportunities they had been given (see Matthew 20:23–24, Matthew 10:15, John 15:24).1
Interpretation 2:
The unbelief of these cities highlights their foolishness (Matthew 11:21). Any Gentile city would have responded differently. Although Tyre and Sidon did not repent when Isaiah (see Isaiah 23:1–18) or Ezekiel (see Ezekiel 26:1–28:26) prophesied against them, they would certainly have repented and turned to the Lord if the mighty works of Jesus had been performed in their streets. Long ago they would have sat in sackcloth and ashes. This shows that Chorazin and Bethsaida—cities bordering the Gentile territory of Tyre and Sidon—were even more foolish than the blind Gentiles of these two other cities.2
21 Malheur à toi, Chorazin! malheur à toi, Bethsaïda! car, si les miracles qui ont été faits au milieu de vous avaient été faits dans Tyr et dans Sidon, il y a longtemps qu'elles se seraient repenties, en prenant le sac et la cendre.